Nathan J O'Callaghan

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We describe a simple and reproducible method to measure absolute telomere length (aTL) using quantitative real-time polymerase chain reaction (qPCR). This method is based on the Cawthon method for relative measurement of telomere length (TL) but modified by introducing an oligomer standard to measure aTL. The method describes the oligomer standards, the(More)
Telomere shortening is an important risk factor for cancer and accelerated aging. Here we describe the development of a simple and reproducible method to measure absolute telomere length. Based on Cawthon's quantitative real-time PCR (qRT-PCR) assay, our method uses an oligomer standard that can be used to generate absolute telomere length values rather(More)
Numerous cytogenetic and molecular studies of breast cancer have identified frequent loss of heterozygosity (LOH) of the long arm of human chromosome 16. On the basis of these data, the likely locations of breast cancer tumor suppressor genes are bands 16q22.1 and 16q24.3. We have mapped the CBFA2T3 (MTG16) gene, previously cloned as a fusion partner of the(More)
The essential role of dietary micronutrients for genome stability is well documented, yet the effect of folate deficiency or excess on telomeres is not known. Accordingly, human WIL2-NS cells were maintained in medium containing 30, 300, or 3,000 nmol/L folic acid (FA) for 42 days to test the hypothesis that chronic folate deficiency would cause telomere(More)
We have previously reported strong evidence for linkage between IBD1 and Crohn's disease (CD) in Australian Crohn's disease families. Three risk alleles for Crohn's disease, (Arg702Trp (C/T), Gly908Arg (G/C) and 980fs981 (-/C), were recently identified in the CARD15/NOD2 gene on chromosome 16, implicating this as the IBD1 locus. Using a novel diagnostic(More)
OBJECTIVE The inflammatory bowel diseases (IBDs), including Crohn's disease (CD) and ulcerative colitis (UC), are multifactorial diseases resulting from a complex interaction of genetic and environmental factors. The recently described CARD15 and TNF-alpha risk alleles are believed to be contributors to disease by disrupting inflammatory pathways via(More)
Deficiencies in folate (FOL) and vitamin B12 (B12) result in increased chromosomal aberrations, a validated biomarker of cancer risk. Telomeres, the regions of DNA that cap the ends of each chromosome, are critical for maintaining chromosomal stability but the impact of micronutrients on telomere structure and function remains unclear. We hypothesized that(More)
OBJECTIVES Excessive shortening of the telomeric ends of chromosomes is a marker of accelerated aging. Oxidative stress and nutritional deficiency may influence this process. The aim of this study was to investigate the effect of ω-3 polyunsaturated fatty acid (ω-3 PUFA) supplementation on telomeric shortening in elderly individuals with mild cognitive(More)
Since the suggestion of their existence, a wealth of literature on telomere biology has emerged aimed at solving the DNA end-underreplication problem identified by Olovnikov in 1971. Telomere shortening/dysfunction is now recognized as increasing degenerative disease risk. Recent studies have suggested that both dietary patterns and individual(More)
Telomere shortening may cause genome instability and is an initiating event in colorectal cancer (CRC). Obesity is associated with reduced telomere length in lymphocytes and is a risk factor for CRC, but the impact of obesity on telomere length in the rectal mucosa is unknown. The purpose of this study was to investigate the effect of weight loss, induced(More)